This article does not cite any sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.Find sources: "Arda River" Douro tributary – news · newspapers · books · scholar · JSTOR (November 2009) (Learn how and when to remove this template message)

.mw-parser-output .hidden-begin{box-sizing:border-box;width:100%;padding:5px;border:none;font-size:95%}.mw-parser-output .hidden-title{font-weight:bold;line-height:1.6;text-align:left}.mw-parser-output .hidden-content{text-align:left}You can help expand this article with text translated from the corresponding article in Portuguese. (May 2021) Click [show] for important translation instructions. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 1,487 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Portuguese Wikipedia article at [[:pt:Rio Arda (Portugal)]]; see its history for attribution. You should also add the template ((Translated|pt|Rio Arda (Portugal))) to the talk page. For more guidance, see Wikipedia:Translation.